Hydrocarbons alkyne series

Compounds consisting of only carbon and hydrogen have the simplest compositions of all organic compounds. These compounds are called hydrocarbons. It is possible to classify the hydrocarbons into four series, based on the characteristic structures of the molecules in each series. These series are known as (1) the alkane series, (2) the alkene series, (3) the alkyne series, and (4) the aromatic series. There are many subdivisions of each series, and it is also possible to have molecules that could be classified as belonging to more than one series. 

The alkyne series of hydrocarbons is characterized by having molecules with one triple bond each. They have the general formula C H2 2. Like other unsaturated hydrocarbons, the alkynes are quite... 

The unsaturated open-chain hydrocarbons include the alkene or olefin series, the diene series, and the alkyne series. The alkene series is made up of chain hydrocarbons in which a double bond exists between two carbon atoms. The general formula for the series is CnH2n, where n is the number of carbon atoms. As in the paraffin series, the lower members are gases, intermediate compounds are liquids, and the higher members of the series are solids. The alkene series compounds are more active chemically than the saturated compounds. They react easily with substances such as halogens by adding atoms at the double bonds. 

The alkyne series of hydrocarbons is characterized by having molecules with one triple bond each. They have the general formula C H2 2 and the name ending -yne. Like other unsaturated hydrocarbons, the alkynes are quite reactive. Ethyne is commonly known as acetylene. It is the most important member of the series commercially, being widely used as a fuel in acetylene torches and also as a raw material in the manufacture of synthetic rubber and other industrial chemicals. 

Figure 13.7 shows the recovery of polyolefins (HDPE, LDPE, and PP) from several plastic waste. Very high polymer recovery was observed for all the plastic waste and proven that pure polymer can be easily recovered from plastic waste by this technique. Both solid and liquid fractions of the recovered polymer mainly consist of aliphatic hydrocarbon (a series of alkenes and alkynes) and can be recycled back into the petrochemical industry as a feedstock for the production of new plastics or refined fuels. 

Another analogous series of unsaturated hydrocarbons that contain just one multiple bond, but, instead of being a double bond, it is a triple bond is the alkynes. The names of all the compounds end in -yne. The only compound m this series that is at all common happens to be an extremely hazardous material. It is a highly unstable (to heat, shock, and pressure), highly flammable gas that is the first compound in the series. This two-carbon unsaturated hydrocarbon with a triple bond between its two carbon atoms is called ethyne, and indeed this is its proper name. It is, however, known by its common name, acetylene. 

The transformation predominates in Group 9 (Rh, Ir) chemistry. Reactions of RhCl(L)2 2 with 1-alkynes give the q -alkyne complexes which slowly convert to the hydrido(alkynyl)s at room temperature. The latter are sensitive to air and not often isolated. Addition of pyridine affords RhHCl(C=CR)(py)(L)2, which readily lose pyridine in hydrocarbon solvents to give square-planar fran.s-RhCl(=C=CHR)(L)2. Alternatively, the Cp complexes Rh(=C=CHR)(L)Cp can be obtained by reaction of the chloro complexes vdth TlCp. In the iridium series, heating for 36h in refluxing toluene afforded the vinylidenes in 80-90% yields. Table 1.2 lists several examples of reactions in which the q -alkyne complexes have been detected. 

Another analogous series of unsaturated hydrocarbons that contain just one multiple bond, but, instead of being a double bond, it is a triple bond is the alkynes. The names of all die compounds... 

There are no other alkynes that are of commercial importance, and so acetylene will be the only member of this series that is considered in fire discussions. There are other alkynes, however, along with hydrocarbons that might have one double bond and a triple bond present in the molecule. 

Alkynes An analogous series of unsaturated hydrocarbons with the general formula C,HM the alkynes all contain just one triple bond between carbon atoms. 

Alkyne ( Acetylene Series). A group of unsaturated aliphatic hydrocarbons of the general formula C, contg triple bonds. 

Solubility-Molar Volume Relationships The correlation between aqueous solubility at room temperature and the molar volume has been studied by McAuliffe [5] for different hydrocarbon classes. He discusses linear relationships, presented as graphs, describing the decrease in solubility with increasing molar volume for the homologous series of alkanes, alkenes, alkandienes, alkynes, and cycloalkanes. 

A long series of papers on the acidolysis of alkyl Grignard reagents by 1-alkynes has been published by Wotiz et al. (for Part XII of this series, see ref. 10). Most of these papers deal with the relative reactivities of various Grignard reagents, as determined11 by evolution of the volatile gaseous hydrocarbon, e.g. 

It has been known for many years that molecular structure of a fuel has a direct bearing on the tendency of that fuel to smoke, i.e., to form carbon or soot in a flame. For example, in 1954 Schalla (41), reporting on a study of diffusion flames, indicated that the rate at which hydrocarbons could be burned smoke free varied in the order n-paraffins — mono-olefins — alkynes — aromatics. This same phenomena has been reconfirmed by many authors in a variety of systems and always in the same general order (j6, J3, J 5, 1 7, J 9, 26, 43, 45). Paraffins have the least tendency to smoke, whereas the naphthalene series have the greatest tendency to smoke. 

Study of the chemistry of such a huge collection of compounds is kept manageable by dividing the hydrocarbons into four main series alkanes, alkenes, alkynes, and aromatic hydrocarbons. 

An alkyne is a hydrocarbon with one carbon-to-carbon triple bond per molecule. The series has molecules with the general molecular formula C H2 2- The first alkyne, called ethyne and commonly known as acetylene, has the formula C2H2 or HC=CH, also written CH CH. Acetylene is used as a fuel in high-temperature welding torches. The alkynes are named similarly to the alkanes and alkenes, but with the ending -yne. 

Carbon is unique in its ability to form long chains of like atoms. Its compounds within each series react similarly, but not identically, chemskiii Builder 24.1 O Aromatic hydrocarbons do not react very similarly to alkenes or alkynes. 

Alkyn s( Acetylene Series). A group of unsaturated aliphatic hydrocarbons of the general formula C Jljn.2, contg triple bonds. These compds were also called Alkines ALL (Propel I ant) is described in conf "Propellant Manual," SPIA/M2, Johns Hopkins Univ, Silver Spring, M aryl an d( 1959), Unit No 406... 

Alkenes are called unsaturated because they contain a C=C double bond and therefore less hydrogen than the corresponding alkanes. They can undergo addition reactions in order to become saturated . The alkanes have no double bonds and all their bonds are sigma bonds between C-C and C-H. They cannot undergo addition reactions because they are saturated already. An even more unsaturated series of hydrocarbons is the alkynes, C H2 -2, which contain a carbon-carbon triple bond, (C=C), made up of a sigma and two pi bonds. The best known member of this series is C2H2, ethyne (also known as acetylene). 

Hydrocarbons consist of only carbon and hydrogen atoms. There are four main series of hydrocarbons, based on their characteristic stmetures alkanes, alkenes, alkynes, and aromatic series. 

Many of the principles of organic chemistry can be developed by examining the series of hydrocarbons in the order alkanes, alkenes, alkynes, and arenes. Alkanes are introduced in this chapter, alkenes in Chapters 5 and 6, alkynes in Chapter 9, and arenes in Chapters 11 and 12. 

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